Viscous-fluid fan couplings for engine cooling systems play a significant role in conserving engine power and enhancing overall vehicle performance.
Electrically-actuated viscous fan couplings (“electrical fan couplings”) have a somewhat high number of parts for providing a precisely-controlled output. Specifically, the typical electrical fan coupling includes a viscous fluid, a working chamber, a reservoir chamber, a series of valve mechanisms, and a computer that actuates the valve mechanisms for metering the flow of viscous fluid between the working chamber and the reservoir chamber. In this way, the computer can control the amount of fluid in the working chamber and selectively engage the coupling to provide a predetermined amount of output.
It would therefore be desirable to provide an improved fan coupling, particularly one having a robust construction comprised of generally few parts.